Briquetting press



L. S. HUBBERT BRIQUETTING PRESS April 9, 1946.

Fil April 2, 1943 FIEz].

4 Sheets-Sheet 1 INVENTOR L=sur-z S. HUBBERT BRIQUETTING PRESS FiledApril 2, 1943 4 Sheets-Sheet 2 FI| .4. IIEnE.

INVENTOR LESLIE S. HUBBERT U -flmiw ATTORN EY April 9, 1946. s. HUBBERTBRIQUETTiNG PRESS Filed April 2,' 1945 4 Sheets-Sheet 3 Plus.

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INVENTOR Lcsu: 5. HuaaERT BY "Ti-M & Tush; ATTORNEYS April 1946. L. s.HUBBERT 2,398,227

BRIQUETTING PRESS Filed April 2, 1943 4 Sheets-Sheet 4 Illll I].

INVENTOR Lssua f3. Hussenr ATTORNEY Patented Apr. 9, 1946 nmounrrmcrnsss Leslie S. Hubbert, Mount Gilead, Ohio, assignor to The HydraulicDevelopment Corporation, Inc., Wilmington, Del., a corporation ofDelaware Application April 2, 1943, Serial No. 481,585

7 Claims.

- This invention relates to presses and, in particular, to briquettingpresses for powdered and granular materials.

It is an object of this invention to provide a briquetting press, inwhich the mold for receiving the material to be briquetted is composedof a plurality of mold parts, movable relative to each other during thepressing operation and adapted, following the completion of the pressingoperation, to cooperate with each other so as to strip the brlquettedarticle from at least one of said mold parts.

It is another object of thi invention to provide a briquetting presshaving a reciprocable mold portion which is positively actuated by thepress ram in response to a predetermined position thereof during theworking stroke of said ram,- and which is operable independently of saidram, following the completion of the working stroke of said ram. 1

It is a further object to provide a briquetting press for forming hollowarticles which includes a reciprocable outer mold portion and areciprocable inner mold portion, and in which said outer and inner moldportions are actuated automatically, following the completion of thebrlquetting operation, to strip the work piece therefrom.

It is still another object of the invention to provide a briquettingpress including a reciprocable mold, composed 01 a plurality of partsmovable relative to each other during the actual briquetting operation,while means is provided opening said mold, following said briquetting operation, to allow removal irregular shape, from the said mold.

These and other objects and advantages of the invention will appear moreclearly from the following specification in connection with theaccompanying drawing in which:

Figure l diagramm tically illustrates a briquetting press according tothe invention.

Figure 2 illustrates, partly in section, an article formed by the pressof Figure 1.

Figure 3 is a wiring diagram for an electric control circuit to be usedin connection with the press according to Figure 1.

Figures 4, 5, 6 and 7 diagrammatically illustrate various phases oioperation of the press shown in Figure 1.

Figure 8 is a somewhat modified briquetting press according to theinvention which is particularly adapted for briquetting irregularlyshapedarticles.

Figure 9 is a view of an article formed in the press constructedaccording to Figure 8.

of articles, havin an Figure 10 is a section along the line Iii-ll ofFigure8.

Figure 11 is a partial section along the line ll|l of Figure 10. Figure12 is a wiring diagram for use in connection with the structure ofFigure 8.

Finsr Emonnmm' Structural arrangement Referring now to the drawings andFigure 1 thereof in particular, the system shown therein comprises apress cylinder having reciprocably mounted therein a press ram 2|.Connected to the press ram 2| is a press platen 22 which carries a moldportion 23 with a bore 24 therein. The mold portion 23 is adapted toenter a molding cylinder 25 provided in and forming a part of a beam orplate 23. The plate 23 has adjustably mounted therein abutment screws orbolts 21 adaptedto be engaged by the platen 22. The plate 26 hasfurthermore connected thereto plungers 23 and 23 which are respectivelyreciprocable in stationarily mounted cylinders 30 Th'e cylinders 33 and3| are hydraulically interconnected by means of conduits .32 and 33. Theconduit 32 is connected to a conduit 34 having one, end in fluidcommunication with the upper end 01' the cylinder 3|, while the otherend of the conduit 34 leads to a 4-way valve, generally designated 35.The 4-way valve 33 may be or any standard design and comprises a valvemember 36 which is continuously urged into its lowermost position bymeans of a spring 31.

In this position, the valve member 36 establishes fluid connectionbetween the conduit 34 and the conduit 33, while simultaneouslyinterconnecting the conduits 39 and 40. The conduit 39 is connected withthe lower portion of the cylinder 3|, while the conduit 40 leads to aconduit 4| one end of which is connected to a 4-way valve, generallydesignated 42. The 4-way valve 42 is of similar structure as the valve35 and comprises a valve member 43 continuously urged into its lowermostposition by means or a spring 44.

In this position, the valve member 43 establishes fluid connectionbetween the conduit 4| and the conduit 45 leading to the lower portionof the cylinder 20, while simultaneously establishing fluid connectionbetween the conduit 43 and the conduit 41 leading into the upper portionof the cylinder 20. Connected to the conduit 41 by means of a pilot line43 is a tonnage control valve, generally designated 43.

u The valves 33 and 42 are provided with solenoids SI and MS,respectively, adapted to counteract the springs 31 and 44 to move thevalves 38 and 42 into their uppermost position. In this position, thevalve member 36 connects the conduit; 34 and 4' with each other, whilesimultanously connecting the conduit II with the conduit ll. Similarly,when the solenoid MS is energized, the valve member 43 establishes fluidconnection between the conduits 4| and 41, while hydraulicallyinterconnecting the conduits 4i and 4'.

The conduit 4| is connected through a conduit II with the pressure sideof a variable delivery pump Ii which may be of any standard design andis provided with control means 52 connected through a pilot line 53 withthe conduit ll for moving the pump ll into substantially neutral or nodelivery position in response to a predetermined pressure in the conduit50. The suction side of the pump II is connected through a conduit 44with afluid reservoir ortank IS. The conduit I4 is connected through aconduit N with the conduit 4| which latter leads to a 4-way valve.generally designated 51. The valve ll corresponds in its structure tothe valves 35 and 42.

The valve member ii is continuously urged into its lowermost position bya spring 5!, in which position fluid connection is established betweenthe conduits 4| and II, while simultaneously the conduits 4. and Ii areconnected with each other. The valve II has also associated therewith asolenoid 82 adapted to counteract the spring 5! so as to move the valvemember Bl into its uppermost position. In this position, the conduit Iis connected with the conduit 4!, while the conduits ll and 4' areconnected with each other.

The conduits I and I lead to the upper and lower portions, respectively,of a control cylinder 2. Reciprocably mounted in the control cylinder 82is a plunger 83 connected to a beam or plate 44 which latter hasconnected thereto adjustable abutment screws 85 for abutment with astationary beam or plate 8|. The plate or beam 8 is also provided withadjustable abutment screws 81 for abutment with the plate or beam 28.

The plate or beam 88 is provided with a sleeve I and furthermore carriesa mold element 69 having the shape of a hollow cylinder and adapted tofit into the molding cylinder 25. The upper surface or the mold element8! forms the greatest part of the bottom of the mold composed of theelements 23, II and 4! and also of the core plunger ll which latter issupported by the beam or plate i4 and extends through the sleeve 68 andthe mold element 6!.

The system shown in Figure 1 also comprises a limit switch LSI which isnormally in open position and is closed by upward movement of the beamor plate 26. A similar limit switch LS3 is provided which is normally inclosed position and adapted to be opened by downward movement of thebeam or plate 20. The beam or plate 84 is also adapted in response to apredetermined position thereof to engage and close a normally open limitswitch LS2, while in another position of the beam or plate 84 the latteropens a normally closed limit switch LS4. The remaining part of thesystem shown in Figure 1 and enclosed by a dot-dash line is notnecessary for the device of Figure 1 it articles, such as the articleshown in Figure 2, are formed, whereas it is useful in connection withthe forming or irregularly shaped articles, such as the article shown inFigure 9, as will be described later.

diagram for the electric control circuit pertaining to Figure i, thisdiagram comprises the main supply line II adapted by closui e oi thenormally open starter switch ST in be connected with the line 12 whichlatter is adapted by closure of the limit switch L8! to be connectedwith a line It. The line 13 is adapted by closure or the limit switchLS2 to be connected with the line I4.

When the tonnage control valve 4! is closed, its switch blade Ticonnects the line 14 with one end of a contactor A, the other end ofwhich is connected with the main supply line II.

The tonnage control blade Ti is connected with a second tonnage controlblade T2 in such a manner that when the blade TI is closed the blade T2is open and vice versa. The contactor A controls the normally openswitches Al and A2 in such a manner that energization of the contactor Acauses the switches Al and A2 to close, while deenergization of thecontactor A causes the said switches to open.

when the switch Al is closed, it electrically connects the main supplyline H through the line ll with the line II. When the switch A! isclosed it connects the main supply line II with one end of the solenoidMS, the other end of which is connected to the main supply line ll.Closure of the blade T2 establishes electric connection between the mainsupply line II and the line II, which latter is electrically connectedby closure of the limit switches L8! or LS4 with one end of thecontactor B, the other end of which is connected to the main supply line14.

The contactor B controls the normally open switches Bl, B2 and B3 insuch a manner that these switches are closed when the contactor B isenergized, while de-energization o! the contactor B causes the switchesBi, B! and B8 to open. Closure of the switch Bl electrically by-pa-smsthe blade T2. Closure oi the switch BI closes the energizing circuit forthe solenoid Bi, while closure of the switch Bl establishes anenergizing circuit for the solenoid 82.

Operation Itmay be assumed that the elements oi Figure 1 so fardescribed occupy the position shown therein, while the mold cylinder I!has been filled with molding material, for instance with powderedmaterial. In order to start a briquetting operation, the operator startsthe pump II and closes the starter switch 3T. Closure of the starterswitch ST establishes an energizing circuit for the contactor A whichcircuit comprises the main supply line H, switches 8T, IBi, LS2,contactor blade Tl, contactor A and main supply line 15.

As a result of the energization oi the contactor A, the contactorswitches Al and A! close. Closure of the contactor switch Al establishesa holding circuitior the contactor A so that the latter remainsenergized when the operatcr'withdraws his hand from the starter switchST so that the latter again opens automatically. Closure oi thecontactor switch A! establishes an energizing circuit for the mainsolenoid MB so that the latter moves the valve member 43 into itsuppermost position.

Consequently, pressure fluid delivered by the pump ii now passes throughconduits II, 4| and 41 into the upper portion oi the cylinder 24 whereit acts upon the ram ii and moves the latter downwardly. The fluidexpelled from the lower portion of the cylinder 2| during this downwardmovement escapes through conduits Ii, 43 and I3 into the conduit I3 andtank ll.

When the ram 2| has moved downwardly to such an extent that the moldportion 23 enters the molding cylinder 25, it begins slightly tocompress the material in the molding cylinder, while the core plunger 13begins to enter the bore 23 in the mold portion 23. It may now beassumed that the mold portion 23 has moved from Figure 4 position intoFigure 5 position so that the platen 22 engages the abutment screws 21.

It will now be clear that further downward movement of the ram 2iactuates the plate or beam 26 through the platen 22 and the abutmentscrews 21 so as to carry the beam or plate 26 along. Consequently, dueto the friction between the material in the mold cylinder 25 and thelatter, pressure is now exerted upon the upper and lower portionapproximately evenly upon the material in the mold cylinder. In thisway, a uniform molding pressure is exerted upon the material in the moldcylinder.

Due to the downward movement of the beam or plate 26, also the plungers23 and 29 move downwardly and pressure fluid in the lower portion of thecylinders 33 and. 3|, respectively, is conveyed through conduits 33, 33and 40 into the conduit 4! from where it is conveyed into the upperportion of the cylinder 23. As a result of the downward movement of thebeam or plate 26, the switch LSI is disengaged and therefore opens.This, however, has no effect on the circuit since the switch L8! isby-passed by the now closed contactor switch Al and the line 16.

When the ram 2| and therefore also the mold portion 23 and the beam orplate 2 have moved from Figure 5 into Figure 6 position, the actualbriquetting operation has been completed. At this time a predeterminedpressure has built up in the upper portion of the cylinder 20 whichpressure is conveyed through conduit 31 and pilot line 43 to the tonnagecontrol valve 49. In response to this pressure, the tonnage controlvalve 49 causes its blade TI to open and its blade T2 to close.

Opening of the blade Tl breaks the energizing circuit for the contactorA so that the contactor switches Al and A2 open. Opening of thecontactor switch Al has no additional eilect at this time, while theopening of the contactor switch A2 breaks the energizing circuit for themain solenoid MS. As a result of the de-energization of the solenoid MS,the spring 33 moves the valve member 43 of the 4-way valve 32downwardly. Therefore, pressure fluid delivered by the pump 52 nowpasses through conduits 50, 4| and 35 into the lower portion of thecylinder 20 and causes the ram 2| to return to its uppermost position.

Closure of the blade T2 establishes an energizing circuit for thecontactor B so that the contactor switches Bl, B2 and B3 close. Closureof the contactor switch Bl establishes a holding circuit for thecontactor B so that the latter remains energized when the tonnagecontrol valve 39 returns to its original position after the pressure inthe conduit 31 has subdded. The closure of the contactor switches B2 andB3 causes energization of the solenoids SI and S2.

As a result thereof, the valve members 36 and 58 move into theiruppermost position. Therefore, pressure fluid delivered by the pump 5|now passes through conduits ll, 43 and 34 into the upper portion of thecylinders 3| and 3c and similarly pressure fluid delivered by the pumpII is conveyed through conduits 3| and 3| into the upper portion of thecylinder I2.

It will therefore be clear that the pressure in the upper portion of thecylinders 33 and 3i causes the plate or beam 23 to move furtherdownwardly into the position shown in Fisure 7. while the core-plunger13 is withdrawn from the molding cylinder 25 as likewise shown in Figure7. In this way, the molded article is stripped from the molding cylinderand the core plunger II and now rests on top of the beam or plate 23.

It may be assumed that while the beam or plate 23 has reached itslowermost position, the core plunger 10 is. still moving downwardly.when the plate 26 has reached its lowermost position it open the switchLS3. This, however. has no eflfect yet on the energization of thecontactor B since the plunger II has not reached its lowermost positionat which it opens the limit switch LS4.

However, when the plunger III has moved downwardly so as to cause thebeam or plate 64 to open the limit switch LS3, th energizing circuit forthe contactor B is broken. The contactor B is therefore de-energized andthe contactor switches Bl, B2 and B3 open. While the opening of thecontactor switch Bl has no additional eifect at this time, the openingof the contactor switches B2 and B3 causes de-energization of thesolenoids SI and S2. Consequently, the springs 31 and 59 pertaining tothe valves 3! and 51, respectively, return these valves to theiroriginal downward position so that pressure fluid delivered by the pump5! causes the plunger 23 and 23 to return the plate or beam 26 to itsuppermost position, while fluid delivered by the pump it into the lowerportion of the control cylinder 62 causes the plunger 63 to lift thecore plunger ll into its uppermost position. The press elements thenagain occupy the position shown in Figures 1 and 4 while, however, thebriquetted article I3 rests on top of the mold element 63.

The operator then removes the article 13 and the mold cylinder 2! may becharged with a new charge of material to be briquetted. Since theplungers 23, 23 and Ill and the ram 2| now occupy their uppermostposition. the pressure in the conduit 50 will increase, to such anextent that, conveyed through pilot line 53, it will cause the controlmeans 52 to move the pump ii to substantially neutral or no deliveryposition. The pump will remain in this position until a new cycle isstarted in the manner described above.

From the above description, it will be clear that the system of Figures1 and 2 comprises a safety feature which prevents the starting of a newcycle before the various parts have reached their initial position. Morespecifically, the closure of the starter switch ST will not be able tocause organization of the contactor A and thereby of the main solenoidMS unless the plate or beam 26 has been fully retracted so as to closethe limit switch LSI, and unless the core plunger 10 has been fullylifted so that the plate or beam 64 closes the limit switch LS2.

mechanism for opening the mold cylinder in order to enable the removalof articles with irregpressing operation,

ular shape, such as the article shown in Figure 9.

More speciflcally, the press shown in Figure 8 comprise a press cylinderll having reciprocably mounted therein a press plunger II which hasconnected thereto a press platen 82. The press cylinder ll is connectedto the press head H, which, in its turn, is connected to the press bed84 by means of strain rods '5 and nuts as. Mounted on the press head 83is a fluid reservoir or tank .1 into which the press cylinder I extends.The fluid reservoir or tank ll corresponds to the tank 55 of Figure l,and the hydraulic connections between the cylinder II, the tank 81 andthe fluid source for delivering pressure fluid to the cylinder II arethe same as in Figure 1. Therefore, the conduits leading to the cylinderll carry the same numerals as in Figure l.

The press bed it carries a plate or beam is which corresponds to thebeam or plate 6 in Figure 1 and which similarly is provided withadjustable abutment screws The beam or plate 88 has connected to theupper portion thereof a mold element SI forming the bottom portion of amold, generally designated 9| (Fig. 11). The mold Si is composed of amold portion 82 which is rigidly connected in any convenient manner withthe movable plate or beam l3, and furthermore comprises a mold portion94 which is movable relative to the beam 13.

The mold portion 94 is slidably mounted on the plate or beam 83 and isconnected in any convenient manner with a fluid operable plunger 95reciprocably mounted in a cylinder 86. The arrangement is such that,during the molding or the mold portions 92 and 94 engage each other soas to act as a unitary form. However, when the briquetting operation hasbeen completed, the mold portion N is spaced from the mold portion 92 inorder to allow the removal of an irregularly shaped article, such as thearticle 91 shown in the drawings.

The structure of Figure 8 is, in a manner, similar to that of Figure 1provided with a control cylinder 98 having reciprocably mounted thereina control plunger as which, in its turn,

has connected thereto a beam or plate IDI corresponding to the beam orplate N of Figure l. The hydraulic connections of the cylinder 98correspond to those of the cylinder 82 and therefore are designated withthe same numerals. Connected to the beam or plate III is a core plungerllli corresponding to the core plunger 10 of Figure l. A further moldportion II! is connected to the press platen II which mold portion isadapted to enter the mold 8i and takes the place of the mold portion 23in Figure 1.

Similar to the structure of Figure 1, the press of Figure 8 is providedwith adjustable abutment screws I03. In order to prevent the hands ofthe operator from accidentally getting between the abutment screws I03and the beam or plate 53, safety guards I at least partially surroundingthe upper portions of the abutment screws I are connected to the platen82.

To limit the uppermost position of the beam or plate 93, adjustableabutment screws ii! are connected to the cylinders I which are connectedto the press head l3. Reciprocably mounted in the cylinders ill areplungers H5 connected to and adapted to reciprocate the beam or plate93. To prevent the operator's hands from getting caught between theabutment screws. H3 and the beam or plate 93, safety guards ill, similarto the safety guards I, are provided and connected to the beam or plateIt. Otherwise, the hydraulic circuit for the structure of Figure 8correspond to that of Figure 1, the only difference consisting in thesupplementary circuit enclosed by a dot-dash line in Figure l.

' This supplementary circuit comprises conduits III and I",respectively, connected to the left end and right end of the cylinder Iand leading to a 4-way valve, generally designated I". The valve illcorresponds in its structure to the valves 35, I2 and 51 and is providedwith a valve member ill continuously urged into its lowermost positionby a spring I". When the valve member III is in its lowermost position,the conduit I" communicates with a conduit iil leading to the conduit5|, while simultaneously the conduit I is connected with a conduit illleading into the conduit H. The valve member III is adapted to be movedinto its uppermost position by energization of a solenoid AS. In thisuppermost position, the valve member ill establishes fluid connectionbetween the conduits I05 and Iii, while simultaneously interconnectingthe conduits IIS and I ll.

Referring now to Figure 12, illustrating the electric control circuitfor the structure of Figure 8, this circuit comprises in part the sameelements as the circuit of Figure 2 which are therefore designated withthe same numerals as used in Figure 2. In addition thereto, the circuitof Figure 12 comprises a normally open limit switch LS5 which is closedby a dog H2 (see Figure 1) when the plunger has properly moved the moldportion 94 into mold closing position.

When the limit switch LS5 is closed, it electrically interconnects thecontactor B and the tonnage control blade Ti when the latter is in itsclosing position. The tonnage control blade TI is furthermore connectedwith an additional tonnage control blade T3 in such a manner that theblade T3 moves into its closing position when the blade Tl moves intoits closing position and opens together with the blade TI. The remainingparts of the circuit shown in Figure 12 will best be understood from adescription of the operation of the structure illustrated in Figure 8.

Operation It may be assumed that all parts of the press shown in Figure8 occupy the position shown therein, while the pump 52 has been started.The operator now closes the switch 0 thereby energizing the contactor A.Energization of the contactor A causes the contactor switches Al and A2to close and the contactor switch A! to open. The opening of thecontactor switch A! has no effect on the circuit at this time.

Closure of the contactor switch AI establishes a holding circuit for thecontactor A so that the latter remains energized when the operatorreleases the switch 0 and allows the latter to return to its openposition. Closure of the contactor switch A! closes the energizingcircuit for the contactor AS so that the valve member I08 moves into itsuppermost position. Pressure fluid from the pump 52 is then conveyedthrough conduits 50, ll, ill and I05 to the right hand portion of thecylinder 96, thereby moving the plunger 95 toward the left and causingthe mold portion 84 to engage the mold portion 52 for closing the mold.

Thereupon, the operator fills the mold II with molding material, andafter this operation has b n o pleted the press is ready to start aworking cycle. To this end, the operator closes the starter switch 8'1thereby closing the energizing circuit for the contactor B which circuitcomprises the main supply line II, the now closed starter switch ST, theswitches LSI, LS2 closed at this time, the blade Tl, the switch L85,contactor B and main supply line 15. Energlzation of the contactor Bcauses the contactor switches Bi and B2 to close.

Closure of the contactor switch Bl establishes a holding circuit for thecontactor B so that the latter will remain energized when the operatorreleases the starter switch ST so that the starter switch returns to itsopen position, Closure of the contactor switch B2 closes the energizingcircuit for the main solenoid 148. Therefore, the valve member 43 movesupwardly, and pressure fluid delivered by the pump ll passes throughconduit 41 into the upper portion of the press cylinder III where itcauses the ram 8| to move downwardly.

The fluid expelled from the lower portion of the cylinder 39 during thisdownward movement of the ram 3| escapes through conduits 45, 4B and 53into the conduit 84 and tank 55. Downward movement of the ram ll causesthe press platen 92 and thereby also the mold portion I02 to movedownwardly. When the mold portion I92 has just entered the mold 9| andslightly compressed the material in the mold, the abutment screws I93engage the plate or beam 93. Further downward movement of the ram M willnow cause the plate or beam 93 by means of the platen 92 and theabutment screws I93 likewise to move downwardly.

Since the cylinder 95 is mounted on the plate 93, the downward movementof the plate 93 carries along the mold 9|. In this way, the moldingmaterial in the mold 9| is properly compressed from all sides. When theplate 93 begins to move downwardly, it disengages the limit switch LSIso that the latter opens. This, however, has no eiiect on the electriccircuit since the contactor B remains energized through the closedcontactor switch Bl. When the plate 93 has been moved downwardly to suchan extent that it abuts the abutment screws 99, it comes to a stop,

At about this time or shortly thereafter, the pressure in the upperportion of the press cylinder 90 has increased to such an extent that itactuates the tonnage control valve 49, thereby causing the blades TI andT3 of the tonnage control valve to open. while simultaneously causingthe blade T2 of the tonnage control valve to close.

The opening of the tonnage control blade T3 breaks the energizingcircuit for the contactor A thereby causing the contactor switches AIand A2 to open, while causing the contactor switch A3 to close. Openingof the contactor switch Al has no e ct on the circuit at this time.Opening of t e contactor switch A2 causes deenergization of the solenoidAS. De-energization of the solenoid AS causes the spring I39 of thevalve II! to move the valve member I99 downwardly, thereby conveyingpressure fluid from the pump through conduit I05 to the left side of thecylinder 95.

As a result thereof, the plunger 95 moves toward the right and spacesthe mold portion 94 from the mold portion 92. The opening of the tonnagecontrol blade Tl breaks the energizing circuit for the contactor B sothat the contactor switches Bi and B2 open. Opening of the contactorswitch Bl has no additional effect on the circuit at this time. Openingof the contactor switch B2 breaks the energizing circuit for the mainsolenoid MS so that the spring 44 pertaining to the valve 42 moves thevalve member 43 downwardly and causes pressure fluid delivered by thepump 5| to pass through conduit 45 into the lower portion of thecylinder 99, where the fluid acts upon the ram ti and moves the latterupwardly. In this way, the mold portion I92 is withdrawn from the mold9|. When the ram 8| has reached its uppermost position, it comes to astop.

Closure of the tonnage control blade T2 brings about energization of thecontactor C so that the contactor switches Ci, C2 and C3 close. Closureof the contactor switch Cl establishes a holding circuit for thecontactor C so that the latter remains energized when the tonnagecontrol valve 49 and thereby the tonnage control blades Tl, T2 and T3return to their initial position after the ram 8| has started its returnstroke.

Closure of the contactor switch C2 establishes the energizing circuitfor the solenoid S2 so that the valve member 59 is moved upwardly andpressure fluid delivered by the pump 5! passes through conduits 4| andGI into the upper portion of the control cylinder 99. Here it acts uponthe plunger 99 and moves the latter downwardly. thereby withdrawing thecore plunger I ill from the mold.

Since the plunger 99 moves downwardly, the extension Ill connected tothe beam or plate I09 disengages limit switch LS2 so that the latteropens. This, however, is without eiiect on the circuit at this time.When the beam I00 has reached its lowermost position it causes the limitswitch LS4 to open. However, inasmuch as the limit switch LS4 isby-passed by the closed switch H8, the opening of the limit switch LS4has no effect on the circuit.

Closure of the contactor switch C3 establishes the energizing circuitfor the solenoid SI so that the valve member 36 moves upwardly'andcauses pressure fluid to pass from conduit 59 through conduits 49 and 34upon the upper portions of the plungers 5, thereby positivelymaintaining the plate or beam 93 in contact with the abutment screws 89.The operator now removes the briquetted work piece from the mold.

To condition the press for a new working cycle, the operator closes theswitch 0, thereby closing the energizing circuit for the contactor A aspreviously mentioned. As a result thereof, the contactor switches Al andA2 close while the contactor switch A3 opens. Closure of the contactorswitch AI establishes a holding circuit for the contactor A, whileclosure of the contactor switch A2 causes energization of the solenoidAS. Energization of the solenoid AS causes the valve member I09 to moveupwardly so that pressure fluid from the pump 5| passes toward the rightside of the cylinder 96 .and causes the plunger to move leftwardly tothereby bring the mold portion 94 into its closing position. When themold portion 95 has reached its closing position, the dog H2 closes thelimit switch LS5.

Opening of the contactor switch A3 breaks the energizing circuit for thecontactor C so that the contactor switches Cl, C2 and C3 open. Openingof the contactor switch Cl has no additional effect on the circuit atthis time. Opening of the contactor switches C2 and C3 causesde-energization of the solenoids SI and S2. De-

energization of the solenoid SI causes the spring .clear that bothcircuits then fully 31 of the valve 35 to move the valve member Itdownwardly.

As a result thereof, pressure fluid delivered by the pump passes throughconduits 50 and 39 into the lower portion of the cylinders i H where itacts upon the plungers H5 so as to move the latter together with thebeam or plate 93 upwardly. when the beam or plate 93 has been fullyretracted, it again closes the limit switch LSI.

De-energization oi the solenoid S2 causes the spring 59 of the valve 51to move the valve member 58 downwardly so that pressure fluid from thepump ll passes through conduit 80 into the lower portion of the cylinder98 and moves the plunger 99 upwardly. In this way, the core plunger liilis again reintroduced into the mold. When the plunger 99 has reached itsuppermost position, the extension III has again closed the limit switchLS2. All parts of the press now are again in their initial position anda new cycle may be started in the manner described above.

While the press shown in Figure 8 has been described in connection withthe briquetting of articles having an irregular shape, such as thearticle shown in Figure 9, which irregular shape prevents an ejection orstripping of the briquetted article in the manner described inconnection with Figure 1, it should be noted that the press of Figure 8may also operate in the manner of the press shown in Figure 1.

To condition the press of Figure 8 for such an operation, it is merelynecessary to shift the selector switch I I! from the position shown inFig ure 9 so that it contacts the terminal I20. Furthermore, the switchH8 is opened. From a comparison of the thus conditioned circuit ofFigure 12 with the circuit oi. Figure 2, it will be correspond to eachother.

In other 'words, the circuit of Figure 12 will then be identical to thatof Figure 2, and since, on the other hand, the hydraulic circuits ofboth presses are the same, Figure 8 will then operate in the same manneras Figure 1.

It is, of course, understood that in this instance the mold portions 92and 94 would be replaced by mold portions making up a mold for acylindrical body similar to the mold cylinder of Figure 1.

When the cylinder 98 of Figure 8 is used, it will be clear that a returnof the plate or beam 93 and consequently a starting of the press cyclewill be possible only after the mold has been closed. This safetyfeature is embodied by the limit switches LS5 and LSI.

It is, of course, understood that the present invention i by no meanslimited to the particular structure shown in the drawings, but alsoembraces such modifications as come within the scope of the appendedclaims.

Having thus fully described and ascertained the nature of my saidinvention, what I claim as new and desire to secure by Letters Patentis:

1. In a press, said press having at least three mold parts at least twooi. which are movable independently of each other and all of which aremovable in unison, a platen motor, a first mold part and a platen rigidwith the movable member of said motor, a second mold part positioned tobe engaged by said platen and to be moved thereby during the latter partof the movement of said platen and first mold part, a third mold partmovable transversely to the direction of movement or said ilrst andsecond a motor means for moving said third mold part into and out orclamping engagement with said and mold part, prior to the engagement ofplaten with said second mold part, said third mold part being alsocapable of movement in the same direction as the second mold part andbeing moved bysaid platen while said third mold part is in clampedengagement with said second mold part and during the latter part of theplaten movement and stop means 10: limiting the movement of all of saidmold parts by said platen motor.

2. In a press, said press having at least three mold parts at least twoor which are movable independently of each other and all of which aremovable in unison, a platen motor, a first mold part and a platen rigidwith the movable motor, a first mold part and a platen rigid with themovable member of said motor, a second mold part positioned to beengaged by said platen and to be moved thereby during the latter part 01the movement oi said platen and first mold part, a third mold partmovable transversely to the direction of movement of said first andsecond mold parts, a transversely disposed motor means for moving saidthird mold part into and out of clamping engagement with said secondmold part, prior to the engagement of said platen with said second moldpart, said third mold part being also capable of movement in the samedirection as the second mold part and hem! moved by said platen whilesaid third mold part is in clamped engagement with said second mold partand daring the latter part of the platen movement and stop means forlimiting the movement of all of said mold parts by said platen motor,and an additional motor means connectedto one of said mold parts formaintaining the same against said step means.

3. In a press, said press having at least three mold parts at least two0! which are movable independently of each other and all or which aremovable in unison, a platen motor, a first mold part and a platen rigidwith the movable member 0! said motor, a second mold part positioned tobe engaged by said platen and to be moved thereby during the latter partof the movement of said platen and first mold part, a third mold partmovable transversely to the direction of movement of said first andsecond mold parts, a motor means for moving said third mold part intoand out of clamping engagement with said second mold part, prior to theengagement of said platen with said second mold part, said third moldpart being also capable of movement in the same direction as the secondmold part and being moved by said platen while said third mold part isin clamped engagement with said'second mold part and during the latterpart of the platen movement and stop means for limiting the movement ofall of said mold parts and platen by said platen motor.

4. In a press, said press having at least three mold parts at least twoof which are movable independently or each other and all of which aremovable in unison, a platen motor, a first mold part and a platen rigidwith the movable member of said motor, a second mold part positioned tobe engaged by said platen and to be moved thereby during the latter partof the movement of said platen and first mold part, a third mold partmovable transversely to the direction of movement of said first andsecond mold parts, a motor means for moving said third mold part intoand out of clamping engagement with said second mold port, prior to theengagement 01' said platen with said second mold part, said third moldpart being also capable of movement in the same direction as the secondmold part and being moved by said platen while said third mold part isin clamped engagement with said second mold part and during the latterpart of the platen movement and stop means for limiting the movement ofall of said mold parts and platen by said platen motor, and anadditional motor means connected to one of said mold parts formaintaining the same against said stop means.

5. In a press, said press having at least three mold parts at least twoof which are movable independently of each other and all of which aremovable in unison, a, platen motor, a first mold part and a platen rigidwith the movable member 01 said motor, a second mold part positioned tobe engaged by said platen and to be moved thereby during the latter partof the movement of said platen and first mold part, a third mold partmovable transversely to the direction of movement of said first andsecond mold parts, a motor means for moving said third mold part intoand out of clamping engagement with said second mold part, prior to theengagement of said platen with said second mold part, said third moldpart being also capable of movement in the same direction as the secondmold part and being moved by said platen while said third mold part isin clamped engagement with said second mold part and during the latterpart of the platen movement and stop means for limiting the movement oi.all of said mold parts by said platen motor, and an additional motormeans connected to said second mold part for maintaining the sameagainst said stop means.

6. In a press, said press having at least three mold parts at least twoof which are movable independently of each other and all of which aremovable in unison, a platen motor, a first mold part and a platen rigidwith the movable member of said motor, a second mold partpositlonedtobcensagedbysaidplatenandtobemovedtherebyduringthelatterpartotthemovementotsaldplltenandflrstmoldparhaflihdmold part movable transversely to thedirection of movement oi said first and second mold parts.amotormeansiormovingsaidthirdmoldpart into and out 01 clampingengagement with said secondmoldpart,priortotlie u-oi'saidplatenwithsaidsecond mold part, saidthirdmoldpartbeingalsocapableotmovementinthesamedlrectionastheseeondmoldpartandbeing moved by said platen while saidthird mold part isinclampedengagementwithsaidsecondmoldpartandduringthelatterpartottheplaten movement and stop means forlimiting the movement of all of said moldpartsbysaid platen motor, and afourth mold part and motor means therefor for advancing said fourth moldpart towardandawayfromsaidflrstmoldpartandin the same direction 01'movement as the movement ofsaidflrstmoldpart.

7. Inapresasaldpresshaflngatleastthree mold parts at least two of whichare movable independentlyoteachother andallofwhich aremovableinunisomaplatenmotonaflrstmold partandaplaten rigidwiththemovable member otsaid motor,asccondmoldpartpositionedtobeengagedbysaidplatenandtobemovedtherebyduringthelatterpartoi'themovementoisaidplatenandflrstmoldmrttathirdmoldpartmovabletothedirectionofmovementofsaidflrstandsecondmoldpamamotormeans for moving said third mold partinto and out of clamping engagement withsaidsecondmold part.priortothetotaidplatenwithsaid secondmoldmrhsaidthh'dmoldplrtbeingalsocapableodmovementinthesamedirectionasthesecondmoldpartandbeingmovedbysaidplatenwhilesaidthirdmoldpartisinclamped twithsaidseeondmoldprtandduringthelatterpnrtotthenlatentand stop means for limiting themovement of all of saidmoldplrtsbysaidplatenmotonandmeam wtoadesiredmaximumpmessuremthe taneouslyopentenidplatenmotmmdanotherofsfldmoldmeanstomoldopmingpoaiflon.

manna.

